Improvement in thermo-electric batteries



M. G. FARMER & H. J. SMITH.

- THERMO ELECTRIC BAR. No. 51,442.

jm erzz ar i fi i-a 2 i Z/ Patented Dec. 12, 18 65.

UNITED STATES PATENT O FICE.

Moses e. FARMEB, 0F SALEM, AND 'HQJULIUS summer o'sron, MAs's- --"IMPIRO VE MENT 'lN THERMO-ELECTRIC BATTERIES.

Specification forming part of Letters Patent N0. 51,442, dated December 12,1865.

To all it mm] concern: v

Beit known that we, Moses G. FARM-ER, of

1 Salem, Essex'jcounty and H. JULI'US SMITH, of Boston, Suffolk county,- all of the 'State .of

Massachusetts,lhave invented an Improved Thermo-Eleetric-Battery Bar; and we do hereby declare that thefoll'owing,take11"in con-1 nectlon with the dra'wingswhich accompany andform' partjof this specification, is ade' scription' of our invention sufficient to enable those skilled in the art to practice it.

'The invention relates to mprovements ,in' thermoelectric batteries.

-"It has recentlybeen pointed {out Marcus 5 that an alloy of twelve parts otf-antimony with five parts of "zi-nc'form's a more energetic negative bar-or plate f r a therino pair-thaniany ot: :thesimple inetalsjhithertp used, This 0001- pound,fhowever, s very-brittle,- and isgext-reinely liable to be broken by careless hand 1 ling and b the unequal expansion or contrac;

tion produced by'alternately heating and coolin g' it. To obviate such d'rflicult-y Zwe strengthen snchbars and render thein much more stable by'casting the alloy-in a mold around or upoua ivirerod or plate of tough metal or other suitaw ble tenacionsniaterial but We find that the elec- (re-motive force "of a thermo pair-isin all cases diminished when the. antimony-zinc alloy' is in contact with such strengthening w re or red,

temperature between' the two ends ofsuch' rod. Rods of steel, however, seem to'actn'p'on theel'ectro-motive force of the pair less preju .tions tr a meme;

probably because a short local circuit is formed I within the metah'owing to the difference of thus protected, does not reduce theforce of the pair. A convenient -method of insulatin g wires or rods for this purpose is to plunge them for a momentlinto melted er-yolite,- or a' mixture of cryolite and floor-spar. It is better,

before immersing the rod, to heat it nearly to the temperature of the melted flux; also to have the surface of the rod clean. Immersion for a few seconds is sufficient for wires of the a size of Nos. 14 or 15, wire gage. Beforecoat l 7 mi ing the wire it is best to bendit into the shape desired, sinceinuch bending after it is coated would cause the covering to crack oflt'.

To'cons'truct our improved bar we place theprepared wirerod, strengthening-bar, or, backbone, as we technically term it, within the mold, or in such relation-to it as to permit the melted alloy, when poured into the mold, to envelop the wire or red moreor less completely,

as may he desired; orwe may so place the strengthening-rod as to be partly or wholly exterier to'the bar, our object being to strengthen the-bar by means ot"s0me tenacious support, and at the same time do no injury to its eflectroqnotive' force, and itis this st rei'igthenjug] of the bur and the insulation of the back bone which constitutes vour'improveinen-tr In large plates we use a number of wires, crossing or'interlaeing them at pleasure.

coarse gauze-of wire, when \vell'coated- "or enameled, is .very' suitable for use in theinterior of large plates.

It. is plain that the positiv e bars of a. thermo pairmaybe strengthened in a similar'way, it

necessar and also other alloys or materials for the negative ,bar besides that'described by -Marcus, .and referred to above.

and B i n'* th e drawingsrepresent secthermo pair embodying ourimprovea denotes the positive bar; b', .the negative bar; 0', thebackbone or strengthening-wire.

'Preterablythis \vireis hentinto' the form shown in the'sections and at G, and it is coated and the alloy melted around it, substantially as abovelset forth.

Whatweelaim is-j- .1. lhe improved thermoelectric bar, con

1 suntan substantially as herein describedniz'.',hy"the=additi0n of some supporting material more tenacious and less liable to be broken than the bar to which it is applied.

'2. Theemployment of an"iusulating-coatingapplied to the supportingrod or wire, for 'thepurpose substantially as set forth In witness, whereof we have hereunto set our hands this-30th day of September, A. D.

Moses GyFARMER. JULIUS SMITH.-

-W,itnesses: i I

J. B. Gnosnr,

F; Gown. 1 

